I'm so confused. section 3.2 in the text book talks about Formal Charges and how they can be calculated by taking the number of valence shell electrons, minus the number of non bonding electrons, minus half of the bonding electrons. The examples in the book look fantastic but whenever I try it on another molecule, I can't get it to work.

For example, question 13 in the lesson practice test 1 for this chapter. The explanation for that question just gives another way of calculating formal charge which isn't in the text book.

I know I'm making some major silly mistake, but I have no idea what it is. Could someone explain to me how to calculate the formal charge on Sulfur in question 13 using the method mentioned on page CHM-27 of the GAMSAT textbook? Its driving me nuts.

Thank you so much